A shear flow turbomachinery device includes a housing having housing walls defining a cavity, a shaft extending into the cavity though a shaft opening in the housing wall at an end of the cavity, a rotor coupled to the shaft within the cavity, the rotor having a plurality of disks extending radially outward from a central axis of the rotor, the disks having a spaced arrangement forming a gap between adjacent disks, and a shroud for shrouding the rotor, the shroud including a pair of end disks coupled to opposing ends of the rotor, a screen extending between outer edges of the pair of end disks, the screen extending around the rotor between the rotor and the housing walls, wherein the shroud is freely rotatable independent of rotation of the rotor to reduce drag on the disks due to the housing walls when the cavity if filled with fluid and the shaft and plurality of disks are rotated.